When Life Is a Zoo

June 4, 2003

Tembo and Zoe are opposite personalities. Zoe, a brainy girl who can't be pushed around, loves people and play. Tembo, on the other hand, is withdrawn and less sure of herself. African elephants at Waco's Cameron Park Zoo, they benefit from a new trend in zookeeping called animal enrichment. Today's progressive zoos are concerned with the psychological health of their charges, as well as with providing basic physical needs such as food, shelter and veterinary care, says Heidi Marcum, senior lecturer in environmental studies and director of animal enrichment studies at Baylor. Cameron Park is accredited by the American Zoo and Aquarium Association, which requires associates to provide enrichment for every captive animal.
Think of it as play therapy for animals. It provides environmental stimuli necessary for optimal psychological and physiological well-being. And talk about a tough crowd to please. If this bunch doesn't like the entertainment you provide, its members can do a lot more than heckle. 
"You can't give up," says Amethyst Hensley, who graduated in May with a degree in journalism. She was one of Marcum's students who worked with several animals at the zoo last summer. "The tigers were very difficult to work with, but you have to persevere. It changed me last summer to see them respond. When we finally found an activity that appealed to them, it was so gratifying. Because of this class, I know I'll always be a zoo volunteer, no matter where I live." 
Some of the students' bigger customers, though, are the easiest to please, Marcum says. "The elephants are lots of fun to work with because they are so intelligent. You can do a lot with them," she says. 
Baylor first offered the three-hour, upper-level environmental studies elective in 2001, and Marcum limits it to 20 students. Although most students in it are environmental studies majors, the program also accepts psychology majors and others with the desire and some experience handling animals. 
Marcum says Baylor has an informal agreement with Cameron Park Zoo, one of the nation's newer natural habitat zoos. "We're partners with them. They've been extremely helpful and supportive," she says.
Marcum first became interested in animal enrichment seven years ago when she began teaching animal behavior classes, which became the foundation for the field course she now conducts. Her research data shows animals that receive enrichment display behavior closer to their wild counterparts -- a subject she has written about for a peer-reviewed journal.
Marcum's motivation for working with captive animals extends beyond the scope of academic research. She believes animal cognition has been underestimated, and her research indicates that virtually all confined animals, not just mammals, benefit from enrichment. "The old thinking that animals only act on instinct is known not to be true anymore, and it is now up to researchers to find out how aware they are," she says.
Marcum requires her students in the summer field class to gather information on natural animal behavior in the wild, with the goal of trying to re-create aspects of that experience for captive animals. Throughout the class, students record differences in animal behavior before and during enrichment. 
"Rhinos have poor vision and hearing, but their olfactory sense is very acute, so we've focused on enrichment with different smells in their habitat," Hensley says. "They surprised us, though, when they showed interest in a toy. We first got it for the elephants, but they didn't care for it."
The "toy" was a large concrete ball, which the rhinos enjoyed pushing around. The keepers, though, didn't share the animals' enthusiasm. "It's so heavy that when it goes into a ditch, it's a problem for the zoo workers to get it out," Hensley says. 
Zookeepers at Cameron Park are pleased with Baylor's interest in animal enrichment. "We do this (enrichment) year-round," says Natalie Lindholm, hoof stock zookeeper. "So it's great to have the students come out and think of creative new ways to keep our giraffes busy. We look forward to it, and we often adopt their ideas for use during the rest of the year." 
Joe Grubic, the mammal and bird curator, says that awareness of animals' needs has grown in the last decade. Cameron Park participates in the Species Survival Plan and houses many endangered or threatened species. "One way we provide enrichment is to mix species that get along with each other. The monkeys' activities cause the birds to do things, for example. By living with other species, they have to compete, adjust, adapt -- just be resourceful."
At least three days a week, the animals receive other stimuli in their habitats. "The activities are not only enriching for the animals, but also for the staff," Grubic says. "It's rewarding to see the animals respond. You can see the curiosity on the animal's face when it notices something different in its habitat." 
In some ways, the African elephants are the most responsive to the new stimuli. They enjoy the attention, relishing their new toys and play, Marcum says. Students often hide apples and other food in the yard for the elephants. They also are fond of frozen watermelons or other fruit frozen in a container of water -- special treats in the Texas summer heat. They roll the items around for a few minutes before stomping on them to get to the icy fruit inside. 
Frozen fruit doesn't interest tigers; they prefer tracking the smell of blood. Last summer, Hensley and Briana Armendariz, a senior from El Paso, Texas, filled a burlap bag with a raw roast, adding bamboo and catnip for filler. They sewed the bag shut, dragged the bait around the tiger habitat and then tied it in a tree. When the tigers were released into their habitat, they tracked the scent and then attacked the suspended bag. When they pulled the bag down, they were rewarded not only with fresh meat, but a tamer version of the thrill of the hunt. 
Long after last summer's class was over, Hensley and Armendariz continued to visit the zoo on Saturdays to provide tiger enrichment, says zoo veterinary technician Mike Niswanger. "They've invented a toy for the tigers we call 'the toy that fights back.' It's the same idea -- a burlap bag stuffed with a roast and bamboo, but they've added a garage door spring to make it bounce back after being attacked." Each cat is about 400 pounds and nearly 10 feet in length, so the rebound of the spring doesn't hurt them.
Niswanger says the lions tend to be a bit more discriminating. They like catnip more than the tigers do and prefer a variety of scents -- even perfume and fruit. "I've hollowed out cantaloupes and filled them with fish. And one of their favorite activities is to destroy pumpkins. It's funny to watch them walking around with a pumpkin in their mouths," he says. 
Lindholm spends much of her time with the giraffes -- Jeffrey, Jenny and Julie -- who share their habitat with greater kudu and marabou storks. "I'm glad enrichment is becoming a topic worthy of investigation by a university," says Lindholm, who has been at the zoo for 12 years. "Even though it's starting to sound trendy, it's really a new concept. Enrichment only became an AZA required standard in 2002." 
Marcum's students have introduced coastal hay, a popular Texas livestock feed, alfalfa pellets and alfalfa hay to test giraffes' preferences. The giraffes liked the alfalfa hay best, so students hide it throughout the animal's habitat. In the wild, giraffes spend their day seeking and eating food, so hiding and scattering food mimics a more natural environment, Lindholm says. "We feed them twice a day, but it's better if they can look around for it and forage all day long," she says.
Although some question the need in any circumstance for captive animals, Marcum says zoos play an important role in preserving endangered species in the wild. "Zoos do raise awareness for animals, for their needs and their plight, but it is the responsibility of their keepers to ensure that captivity is not prison but a good life that satisfies the animals' instinctual motives," she says. 
The ultimate goal is to provide an authentic enough habitat for animals so that they would not know they are captive, Marcum says. "Captivity is inevitable for some animals, and I want to do whatever I can to make their lives as good as they can be," she says. "My passion is to relieve the suffering of all animals, one animal at a time." 

Long is the media relations science writer in the Baylor Office of Public Relations.